The present invention relates to a system for reading at least one data item written in a memory of an electronic component, and also to a method of reading at least one such data item.
A particularly advantageous application of the invention lies in the field of electronic memory cards, in particular cards in which the memory contains data relating to the results of transaction operations, e.g. as performed by means of said cards, for example units remaining in a phone card or credit available in an electronic purse.
In very general terms, electronic components in memory cards are designed to be capable of communicating and exchanging data of various types with the terminals with which they are connected for the purpose of effecting the operations which are to be performed. In particular, the procedure of setting up communication includes an initial stage during which the electronic component receives an initialization signal from the terminal, and then in turn sends an xe2x80x9cinitialization responsexe2x80x9d message to the terminal, which message contains the information required by the terminal to establish dialog with the component.
Systems are also known for reading data from an electronic memory card, which systems are essentially constituted by a housing into which the card is inserted so as to establish electrical contact between the electronic component and a connector contained in the unit. Said unit also includes software in a read only memory (ROM) enabling data to be interchanged with the electronic component for the purpose of reading data from the memory of the component and displaying said data on display means, such as a liquid crystal display screen.
Nevertheless, those known reader systems suffer from the drawback that the software used must be adapted specifically to the card whose data is to be read, and as a result it is necessary to store as many pieces of software in the memory of the unit as there exist types of cards to be processed, which takes up a relatively large amount of room in the unit due to the size of the memory.
Published Document WO-94/23399 describes a read system in which for the purpose of reading n DATA items, it is necessary to insert the card into the reader n times and to withdraw it n-1 times. In parallel with reading a data item DATAn, a pointer signifying xe2x80x9cDATAn readxe2x80x9d is written in the EEPROM of the card. The multiple withdrawals and reinsertions of the card in the reader constitute handling operations that are tedious to perform. Untimely withdrawal of the card at the moment that writing is taking place in the EEPROM can give rise to integrity defects in the data written in the memories.
An object of the present invention is to provide an improved technique for reading at least one data item written in a memory of an electronic component, said electronic component being suitable for communicating with a terminal and in particular for issuing an xe2x80x9cinitialization responsexe2x80x9d message in response to an initialization signal issued by said terminal.
This and other objects are attained in accordance with one aspect of the present invention which comprises:
in the electronic component, searching means for searching for the data item in the memory and for writing said data item in an initialization response message zone; and
a reader unit comprising:
means for issuing said initialization signal when the electronic component is connected to the unit; and
means for reading the data item in said initialization response message zone.
The procedure for initializing electronic memory cards, i.e. the formats of the initialization signal and of the initialization response message, are standardized by the standard ISO 7816-3, which is hereby incorporated by reference so it will be understood that the data reading system of the invention is of universal nature and can be used with all existing cards. This means that the system is simplified considerably compared with systems known in the state of the art, thereby making it possible to reduce the size of the reader unit.
In accordance with the invention, it is advantageous for said unit to have display means for displaying said data, after it has been read, thereby enabling the user to inspect visually the value of the data item read by the system of the invention.
In accordance with another aspect of the invention, in order to enable a plurality of data items written in the memory of a single electronic component to be read, the invention provides for said unit to be provided with forced initialization means for enabling said means for issuing an initialization signal to be actuated at will so that the data written in the memory in locations numbered 1 to N, can be read cyclically and in sequence on each actuation of said forced initialization means, with the data in location 1 being read on the electronic component being connected to the unit.
Advantageously, the read system in accordance with a specified aspect of the invention includes an electronic component that further comprises a volatile memory in which data is written indicating that data item DATAi has been read or that data item DATAi+1 is to be read, and means enabling the power supply to the electronic component to be conserved during cyclic reading in sequence of the data items DATA2, . . . , DATAN.
A further aspect of the present invention provides a read method for reading at least one data item written in a memory of an electronic component, said electronic component being suitable for communicating with a terminal, and in particular for issuing an initialization response message in response to an initialization signal issued by said terminal, the method being characterized in that it comprises the following steps, in which:
the electronic component is connected to a reader unit;
the unit issues an initialization signal;
the electronic component searches for the data item in the memory and writes said data item in an initialization response message zone; and
the data item is read from said initialization response message zone.
Yet another aspect of the invention further includes the following step, in which:
forced initialization means actuate the initialization signal (SI) issuing means so that for the data items DATA1, . . . , DATAN written in the memory being numbered 1 to N, with the data item DATA1 of rank 1 being read as soon as the electronic component is connected to the unit, and the data items DATA2, . . . , DATAN being subsequently read cyclically and in sequence on each actuation of said forced initialization means. When a data item DATAi is read, a volatile memory of the component is written so as to contain data signifying that the data item DATAi has been read or that the data item DATAi+1 is to be read. To read a data item DATAi, the state of the volatile memory is verified. The power supply to the electronic component is maintained throughout cyclical reading of the data items DATAi.